Ahhh, the old "prove it's a scam" challenge. If proof was so easy to find, there wouldn't be scams. 1manband gave you ample circumstantial proof, that would be more than enough for most folks to run in the opposite direction from this so-calling mining company.
But you are looking for direct proof. You say you did lots of DD, but did you hire your own third-party consultant to review the data or come along on the site visit? I doubt it. Or are you a placer mining expert? I doubt that too.